Refrigerator and evaporator therefor



April 10, 1951 w. L. MoRRlsoN REFRIGERATOR AND EvAPoRAToR THEREFOR '7 Sheets-Sheet' 1 Filed May26, 1945 April l0, 1951 I w. L.. MORRISON 2,548,441

REFRIGERATOR AND EvAPoRAToR THEREFOR Filed may 2e, 1945 -7 sheets-sheet 2 w. MoRRlsoN 2,

'7 Sheets-Sheet 5 REFRIGERATOR AND EVAPORATOR THEREFOR April 10, 1951 Filed May 26, 1945 April 10, 1951 wa MORRISON 2,548,441

REFRIGRATOR AND EVAPORATOR THEREFOR Filed May 26, 1945 7 Sheets-Sheet 4 @EMM @Cuir/L .April 10, 1951 w. MORRISON 2,548,441

REFRIGERATOR AND EVAPORATOR THIEREFOR April 10, 1951 W. L. MORRISON REFRIGERATOR AND EVAPORATOR THEREFOR Filed May 26, 1945 '7 Sheets-Sheet 6 April 10, 1951 w. MORRISON 2,548,441

REFRIGERATOR AND EvAPoRAToR THEREFOR Filed May 2e, 1945 7 sheets-sheet v 3 evaporator and the inner face of the wall |9. Part of the ducts I6 and I8 may be enclosed within the housing I9 and may be surrounded by the insulation. 22 is any suitable top seal of nonconducting material which closes the top of the previously mentioned loose insulation 2i. 23 is an inner ring of insulating material. 24 is a top closure which may be metal or plastic andwhich is shown as resting upon the heat insulating ring 23, so that there is no heat transmitting connection 1tween the outside and the inside of the structure. However, it may be advantageous to employ heat insulating material, a plastic or the like, for the ring 24. 25 is any suitable top cloa handle 26, for access to the storage space surrounded by the evaporator.

With reference to the interior structure of the evaporator, a cylinder of mesh or netting 21, of any suitable metal, is shown as positioned in the space between the cylinders 1 and 9. It constitutes a distributing and delaying element for the refrigerant as the evaporating refrigerant flows downwardly through the evaporator between the opposed faces of the cylinders 1 and 8. The layer 21 of mesh may be compressed between outer and inner cylinders and may constitute spacing means for establishing the radial separat-ion between the cylinders 1 and 9. Or any suitable spacing means may be employed.

In the form of Figures 4 and 5, I illustrate a similar structure used as an open ended refrigerating or cooling element, which may be used for room cooling, air cooling or the like. The inner cylinder 1a is therein shown as open ended. The outer cylinder 9a surrounds it and is sealed to it at the end as at Illa and llaa.A The mesh 21a is compressed between the inner cylinder 1a and the outer cylinder 9a. `The evaporator is preferably but not necessarily generally upright.

In any event, a volatile liquid refrigerant is delivered at low pressure,` to the interior of the .plenum chamber |2a through the duct Ilia. The

vaporized refrigerant flows from the opposite l plenum chamber |565 along the discharge duct or suction line |8a.

With reference to the form of Figures 6 to 9 the structure is the same as shown in Figures l and 2 except for the below described top diserant under reduced pressure is received in the rirg 3| from the duct 33. The ring 3| constitutes a circumferential distributor which insures that the liquid refrigerant flows downwardly toward the upper edge of the mesh 21 at a substantially uniform concentration throughout the circumference of the evaporator. The outlet passages 32 may be so proportioned to the rate of liquid refrigerant delivery as to obtain this result. In this form, as in the preceding forms,

the refrigerant flows continuously through andV about `the evaporator.

In Figure l() the distributor ring 3|a serves as the top closure for the space between the cylinders 1 and 9. In that form the outer cylinder 9 has an outward offset portion or flange 9c upon which the distributor ring 3|a rests. The ring is Vturned to the compressor,

4 `welded or otherwise suitably secured in sealing relationship, to the flange 9c and to the upper edge of the inner cylinder 1.

Figure l1 may be taken as a distortion or unfolding of a cylindrical evaporator, but indicates primarily a relatively fiat evaporator or cold plate formed by opposite sheets of metal 40 and 4|, having the mesh or netting 2lb positioned between them. A top plenum chamber 42 and a bottom plenum chamber 43 may be formed between the two plates. In Figure 12 the plenum chambers are both formed as distortions from the plate 4|. It may be understood, however, that they may be formed in either plate or by an aligned distortion of both plates. The plates 4B and 4l may be sealed at all edges as at 4|a.

The refrigerant may iiow through the inlet i4 and the evaporated refrigerant returns to the compressor through the return duct or suction line l5 which will be understood to extend downhill to the compressor, it beng thought unnecessary to illustrate the compressor again, since the relationship of the passages between the evaporator and compressor is intended to be the same as that shown in Figure 1. Since fiat plates are involved, which are not self-sustaining by their cylindrical form, I employ any suitable spacing and connecting means. I illustrate for example spot welded connections 46, the two plates 4d and 4| being welded together through the mesh 21h. I may also employ a spacer or spacers :i1 to which the plates 40 and 4| may be riveted or otherwise secured. I thus obtain the double result of maintaining a proper spacing between the plates 45 and 4| and of holding them against internal pressure. It will be understood that a spacing and securing means shown in Figures 1l and l2 may, if desired, be employed in such evaporators as shown in Figure 2. However, under most circumstances this is not necessary.

In Figure 13, I illustrate a modified structure in which on the base 5|) I position any suitable compressor 5| driven by a motor 52. The evaporator, generally indicated as 53, rests upon the insulating disc 54 and is surrounded by an outer housing 55 between which and the evaportor any suitable insulation 56 Vis employed. The evaporator includes an outer cylinder 53a and an inner cylinder 53h, the cylinders being secured in sealing relationship at top and bottom as at 53e and 53d.

The compressed refrigerant iiows through any suitable condenser 51 and may now directly from the condenser, without any intermediate receiver, along the high pressure liquid delivery duct 58, through any suitable pressure reducing means 59 to the top inlet assembly 60 through which the refrigerant is delivered, at reduced pressure, to the space between 53a and 53h. As delaying and distributing means I employ, in the forms of Figures 13 and lli, a spiral strip 62 of sheet metal or the like which starts Vat the top of the inner cavity of the evaporator, dened between the Walls 53a and 53h and terminates at the bottom. It derines a spiral passage through which the refrigerant hows downwardly as it evaporates. An outlet duct 63 delivers the evaporated refrigerant to a small horizontal accumulator 64 in which any unevaporated refrigerant may be evaporated, so that substantially no liquid refrigerant is re- The evaporated refrigerant returns to the compressor downhill along the suction line 65. 66 is any suitable insulating means or layer whereby the accumuf later -64- is somewhatL insulatedi-from theeevaporator. In the- `form of Figures '13 and 14 lit will be understood thatthe strip 62 defines a--wide but radially veryv shallowV passage" through Vvwhich the refrigerantflows'duringhevaporation and by which it is constrained ,to -an velongated path passing va number of times-about the evaporator. However, the stripZ is not welded or permanently secured, except sofar as it may be necessary :to spot Vw-eld it ata-,few points for positoning. The clearance is such that the refrigerant can escape across bends of thestrip 62, to the end that the inner cylinder '53h constitutes through its `entire surface a direct refrigeratng member, with the evaporating refrigerant passing across its `entire outer areafthe spacetoibe cooledbeing surrounded by its entire inner larea. Inithis form I do not employ plenumchambers at all and find that the spiral passage system, or the spiral member 62 maintains an adequate distribution of the refrigerant throughout the area of the evaporator, and holds back the refrigerant from an unduly or direct passage downwardly through the evaporator.

In the form of Figures 16 and 1'7 I substitute for the separate spiral members 62 a spiral passage formation obtained by distorting one of the cylinders toward the other. In this form I illustrate an inner cylinder 'l and an outer cylinder 1|, the two cylinders being sealed together at top and bottom as at l2 and 13. One of the cylinders may be distorted toward the other to form a spiral passage by the spirally distorted portion 'M Whereas I illustrate the outer cylinder as somewhat distorted, it will be understood that the inner cylinder may be distorted or the passage may be formed by an opposed and aligned distortion of both cylinders. Where the evaporator is used as a storage container, however, it may be advantageous to have a smooth inner face defining the storage space, as shown in Figures 16 and 17.

In the form of Figures 18 and 19, I illustrate a generally flat evaportor lying in a substantially horizontal plane. It may be formed by an upper plate ||I|l and a lower plate ||l| sealed together about the edges as at |02. Liquid refrigerant is delivered at reduced pressure through the inlet duct |3. The evaporated refrigerant is withdrawn from the opposite end of the evaporator by the suction line |64, which flows downhill to the compressor N15, thence through condenser I, and pressure reducing means to the inlet duct |03, in the manner explained in the system shown in Figure 13. Any suitable spacing means may be employed for spacing the opposite walls of the evaporator apart, such as the netting |08.

The form of Figure 18 has in common with the systems of the other drawings that a liquid refrigerant is delivered to the evaporator having a substantially restricted internal space. The refrigerant is entirely or substantially entirely evaporated in the evaporator, without flooding the system. The evaporated refrigerant is withdrawn by the suction line and is returned downhill to the compressor.

Wherever I use the term downhilL I will be understood to intend that the relation between the inlet and the outlet is such that any liquid which travels with the evaporated refrigerant will be carried through, without gathering in any pocket or being trapped by gravity in any part of the system.

Figure 20 illustrates a for-m of structure substant-ially 'the-same as Fthat of Fi'gure'Z'f-@except forme-:elimination ofi'the-imeshf21. "I therefore clearance is itself sufficient Vto hold-.back Vorildelay the downward passage ofztheffrefrigerant,giving 'through the suction returnlinei 8e.

It will be realized that, whereas, I .'haveffdescribedv and illustrated. a=practioal and-operative device, neverthelessmany. changes' may be`V made inthe size, shape, number and disposition-of parts without departing 'from the spirit A.of -my invention. I therefore'vwish `'my descriptionian'd d-rawings to-be taken-as in-a broadsense' illustrative or diagrammatic, rather than as limiting me to my precise showing.

I claim:

1. In an evaporator for refrigerators and the like, an inner cylinder and an outer cylinder, said cylinders being sealed together to dene therebetween a space for the evaporation of a volatile refrigerant, the axis of said evaporator being generally upright, a refrigerant supply duct extending to the'upper end of said space, a refrigerant return duct extending from the bottom of said space, means for circulating a refrigerant through said ducts and space, and means for distributing the refrigerant substantially uniformly throughout said space while maintaining a generally downward movement of the refrigerant throughout said space, whereby substantially all of the outer face of the inner cylinder is subjected to the evaporating refrigerant, said inner cylinder constituting, substantially throughout its entire area, a primary refrigerating surface.

2. In a refrigerating system, an evaporator including an inner cylinder and an outer cylinder, said cylinders being sealed together to define therebetween a space for the circulation and evaporation of a volatile refrigerant, the axis of said evaporator being generally upright, a compressor and means for actuating it, a condenser, a high pressure duct extending from said compressor to said condenser, a high pressure duct extending from said condenser to the top of the space between said cylinders, pressure reduction means between said duct and said evaporator, a return passage extending from the bottom of said space to said compressor, said return passage being adapted to conduct the refrigerant downhill to said compressor, whereby the refrigerant travels continuously downwardly from top to bottom of the evaporator and downwardly from the bottom of the evaporator to the compressor, and means for maintaining a substantially .uniform distribution of the refrigerant about the circumference of the evaporator during the downward movement of vthe refrigerant through the evaporator.

3. In an evaporator for refrigerators and the like, an inner cylinder and an outer cylinder, said cylinders being sealed together at the top and bottom to define therebetween a space for the evapora-tion of a volatile refrigerant, a, refrigerant supply duct extending to the upper end of said space, a refrigerant return duct extending from the bottom of said space, means for circulating a refrigerant through said ducts and evaporator, and means for distributing the refrigerant throughout the space between the two cylinders, including a thin metal insert positioned between the two cylinders, the radial clearance between the two cylinders being substantially uniform from top to bottom of said space.

4. An evaporator for refrigerators and the like including an inner and an outer cylinder sealed together to dene between them a space of substantially uniform radial Width from top to bottom of the evaporator for the evaporation of a volatile refrigerant, the axis of the evaporator being generally vertical, a refrigerant supply duct extending to the upper end of said space and a refrigerant return duct leading from the bottomthereof, means for circulating a refrigerant through said ducts and said space and means for distributing the refrigerant substantially uniformly throughout said space, including the opposed walls of said cylinders and associated 8 means for forming' a spiral passage extending from the supply duct to the return duct while permitting leakage across the outer face of substantially the entire surface of the inner cylinder to permit subjection of substantially all the outer face to the evaporating refrigerant.

WILLARD L. MORRISON.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,960,975 Mulch May 29, 1934 1,985,381 Richards Dec. 25, 1934 2,408,805 Millott Oct. 8, 1946 2,446,763 Haymond Aug. 10, 1948 

